Conventionally, various types of separation membrane elements such as tubular type, hollow fiber type, spiral type, and pleated type elements are used to concentrate raw fluids such as liquids and gasses or to separate specific components from the raw fluids. For example, Patent Literature 1 describes a spiral separation membrane element having a wound body including separation membranes, a feed-side carrier material and a permeate-side carrier material that are spirally wound around a core tube.
In a spiral separation membrane element, in general, a wound body is joined to a core tube at both axial ends of the wound body. For example, Patent Literature 2 describes that two rectangular separation membranes and a permeate-side carrier material sandwiched therebetween are bonded together with an adhesive along the three edges of each of the membranes and the carrier material so as to form an envelope to be spirally wound around a core tube, and the resulting wound body is bonded to the core tube at the end faces of the wound body, using the adhesive of the two opposite edges of the envelope.
When a spiral separation membrane element is used, the spiral separation membrane element is loaded in a cylindrical pressure vessel and a pressure difference is given between the feed side and the permeate side with the separation membrane interposed therebetween while a raw fluid is passed through the pressure vessel. Thus, concentration or separation through the separation membrane takes place.
Spiral separation membrane elements may be exposed to high temperature environments in some applications. For example, when a spiral separation membrane element is used for processing treatment of foods, medicines and fine chemicals or waste water treatment after the processing of them, high-temperature treatment water or treatment water vapor is fed into the spiral separation membrane element. In a spiral separation membrane element used for extraction of alcohol, etc. using a pervaporation (PV) method or a vapor permeation (VP) method (see, for example, Patent Literature 3), high-temperature vapor generated from a high-temperature aqueous solution permeates through a separation membrane.